Propeller.



f J. M. RITOHIE.

PROPBLLER. APPLwATIoN FILED JULY 16, 1912A Patented Jan. 19, 1915.

2 SHEETS-SHEET l.

J. M. RITGHIE.

PROPELLER. APPLICATION FILED JULY 1o, 1912.4

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Specification of Letters Patent.

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Application filed July 16, 19153. lSerial No.I 7093i?.

Tovall whom 'it may concern:

Be it known that I, JACOB M. Rrrorint,

a citizen ofthe United States, residing atv Michigan City, in the county of Laporte and State of Indiana, have invented newv and useful Improvements in Propellers, of

which the 'following is a specification.

This invention relates vto propellers and more particularly to aeroplane propellers.

One of the principal objects of the inventionis to provide asimple and efficient device of this character which may be reversed while the engine is running at full speed so that, should the aviator break a wing or otherwise damage his machine, .and start to falling head first, he could reverse the propeller, and by this means sustain most of the weight .of the machine or all of it so that the force of gravity would be reduced or offset, whereby the fall is made `light and practically no damage will result.

Further objects of this invention will appear as the followingspeciiic description read in connection with the accompanying drawing, which forms a part of this appli'- cation, and in which Figure 1 is a `detail side elevation showing the propeller' mounted upon a portion of an aeroplane. Fig. 2 is a vertical section on the line 2-2 of Fig-1. Fig. 3 is a vertical longitudinal section. Fig. 4 is a horizontal longitudinal section taken on the line 4 4 of Fig. 1. Fig. l5 is a perspective view of the rack frame. Fig. 6 is an elevation of one of the gear segments. f 4

Referring more particularly to the drawing, 1 represents a supporting part upon an aeroplane or other type of air ship and mounted upon this part are suitable bearings 2 in which the engine or propeller shaft 3 is journaled. The outer end of this shaft is squared, as shown at 4, so as to enter a squared socket 5 formed in the head 6 of the propeller hub 7. This propeller' hub is hollow so as yto receive a rectangular rack frame 8 to be hereinafter described. lThe shaft 3 has sli dably mounted thereon a sleeve 9 which is threaded into one end of the rack frame, as shown, and the threads preferably running in a direction opposite to the travel grooved collar v10 which is provided with a shifting ring 11 lying in the groove and having laterally extended pins 12 which are engaged by the bifurcated lever 13 upon the support l, The lower ,end of the lever 13 is connected by means ofthe link 14 to a controlled lever 15 also pivoted upon the support and operating over a notchedsegment 16 which .is adaptedtohe engaged, by the spring pressed pawl 17 forl locking the lever 1n adplsted position. When this lever is operated in either direction, the sleeve I9 and consequently the gear frame 8 will he shifted upon theshaft 3, and in order to prevent the shock which would otherwise occur if the frame werev allowed to strike the opposite ends ofthe huh, there is secured in the ends of the hub, suitable cushioning buffers 18.

The` jfrat-ne 8 comprises the squared endy plates 19 and 20 connected together at each corner by bars 21 and 22, the latter of which' i have a reduced portion 27 which is journaled in the hub and a further reduced and squared portion 28 which enters the squared apertures 29 formed in each segment. rlhe upper or outer ends of the heads 25 are suitably flanged, as shown at 29, and to these flanges are secured the propeller bla des 30. In order to secure a more firm bearing forthe heads 25, the same are provided with recesses'in their ends, as shown at 31, to receive the ends of the engine or propeller shaft 3. W'hen the lever 15 is shifted to its rearward position, the rack frame will be moved rearwardly in the hub and the rack faces being in engagement with the toothed segment, will cause said segments to turn and the propeller blades will be thereby rotated so as to change their position.

It will be noticed that this invention has many advantages outside of the ones previously recited. For instance, if an aviator desires to alight or to coast, dip, or dive, he may readily setthe propeller blades to a neutral or intermediate position without stopping his engine, and in this position, the engine may be started without having any one to hold the machine while the engine is being tuned up or obtaining its required speed. ly then throwing the lever forward, the propeller blades may loe turned so as to throw them into operative position for starting the flight or for continuing the same after coasting. If the aviator desires to alight after a flight, and finds that his speed is too great for safety, h e may reverse the propellers and slacken up the speed without cutting out his engine. This same procedure may also be adapted, as before stated, to sustain or partially sustain the machine in case of broken parts. It will, of course, be also understood that this type of propeller may'be readily used with vmotor boats and like devices.

What is claimed is Y In a reversible propeller, the combination of aA hollow hub, a driving shaft passing through the hub and being connected fixedly therewith, radial propeller blades journaled in the hub, a vrack frame slidably mounted within the hub for longitudinal movement and being. provided with longitudinal slots having parallel longitudinal walls, a toothed rack `formed upon one longitudinal wall of 2g each frame slot, an operating segment mounted lIixedly -upon the inner end of each propeller, eachV segment being substantially lsquare in form and having two opposite corners thereof rounded concentric to its axis, the opposite rectangular corners of the segment being adapted to provide flat limiting faces, gear teeth provided upon one of the rounded corners -of each segment for engagement with the rack of the corre-v sponding frame slots, each operating segment being longitudinally movable within the corresponding frame slots and having its limiting faces adapted for engagement with the opposite longitudinal walls of the slot, parallel limiting faces of the segments in presence of two Witnesses.

JACOB M. RITCHIE. Witnesses:

L. A. THAYEB, E. KING. 

